SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c0cb90ff52a2facec11f8b87fe36e77a7f3a658690859593d689b68a66cb419f' 
  AND token = 'WvcEujY7JfTwxuiqO4+Rab2kLkoOxT7M2mbdrjTF3tk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}